Apparatus for the spinning of cuprammonium filaments



Oct. 2, 1934. HARTMANN ET AL 1,975,575

HE SPINNING 0F CUPRAMMONIUM FILAMENTS APPARATUS FOR T Filed- Dec. 51, 1931 niz Jn Patented Got. 2, 1934 AFPPARATUS FOE THE SPINNENG OF CUPRAF/[MQNEUM FILAMIENTS August Hartmann and Walter Hiifinghoff, Wuppertal can Bemberg Corporatien,

Barmen, Germany, assignors to Ameri- New York, N. Y., a

corporation of Delaware Application December 31, 1931, Serial No. 584,222 In Germany March 5, 1931 4 Claims.

This invention relates to a method of and apparatus for the manufacture of artificial silk and the like.

One object of this invention is to provide a suitable method of spinning artificial silk and the like which will result in a considerable saving of material over the methods now in use.

Another object of this invention is to provide a suitable apparatus which will permit of a con- *siderable saving of the ammonia used to form the spinning solution.

A further object of this invention is to provide suitable means for the production of artigficial silk and the like which will reduce the loss of ammonia due to evaporation.

7255 construction and are supplied with a suitable coagulating or hardening solution by means of an inlet pipe 2 connected to the mixing container 3 through the main line 4. The freshly spun filaments and the coagulating or hardening liquid pass downwardly through the spinning chamber and the former then pass over a rod or suitable direction changing means 5, through an acid guide 6 and are then wound on a suitable reel or swift '7.

A large portion of the coagulating or hardening liquid is deviated from the path of the freshly spun filaments by means of an outlet tube 8 located above the exit opening 9 for the filaments. The amount of the treating liquid which fiows out of the tube 8 may vary, but in practice,

amounts to about 90% of the total treating liquid used. That portion of the treating liquid which passes through the exit opening 9 falls into a gutter or trough 10 and is led by suitable 5"collecting means to ammonia recovery tanks.

The treating liquid, passing through the outlet tube 8, is led by means of a suitable pipe line 11 to a circulating pump 12. The pump forces the treating liquid through the pipe 13 to the 0 mixing container 3, the direction of the flow being indicated by the arrow.

A certain amount of water is mixed with the used treating liquid and is supplied thereto by means of a pipe 14 connected to the pipe line '13. A valve 15 is provided on the pipe 14 to regulate the flow of the water into the pipe line 13. The mixing container is provided with means 16 to deaerate the treating liquid at the beginning of the process.

In operation a suitable spinning solution is iorced through a spinning nozzle into the spinning chamber, where, contacting with the treating liquid conveyed thereto from the mixing container through the inlet tube 2, becomes somewhat hardened or coagulated. The treating liquid passing through the spinning chamber with the freshly spun thread or filaments, stretches and further hardens the same. The ammonia of the spinning solution, because of the precipitation of the cellulose, passes into solution in the treating liquid. About 90% of the treating liquid, now containing ammonia in solution, is deviated from the path of the downwardly moving thread and is passed through the closed circulating system, back to the mixing container and again used to coagulate or harden the filaments. The ammonia concentration in the treating liquid thus is regularly increased. Hence that portion of treating liquid which falls into the gutter or trough contains a large percentage of ammonia making the recovery thereof economically possible. By using a closed recirculating system such as has been described, the evaporation of ammonia is practically eliminated.

From the above description it will be appreciated that there has been provided a simple and .efiicient method and means whereby the recovery of ammonia may be made economically feasible and any loss of the ammonia due to 9'0 evaporation is practically eliminated.

Although there has been shown and described a specific apparatus and a particular process as adapted for being carried out in the use of that apparatus, it is to be understood that the invention is not to be restricted to the details of the method, or, insofar as the method is concerned, to any specific apparatus except as may be specifically set forthin the claims hereto appended.

What is claimed s new is:

1. In an apparatus for use in the production of cuprammonium filaments, in combination, a spinneret arranged at the top of a spinning chamber, an inlet for precipitating liquid leading into the chamber, an outlet for the precipitating liquid at the lower end of the chamber, a by-pass means located above the lower end of the spinning chamber, whereby a portion of the precipitating liquid may be deviated from said 110 chamber, and means for returning said used precipitating liquid to a storage tank the entire system being closed so that air is excluded.

2. In an apparatus for use in the production of cupramrnonium filaments, in combination, a spinneret arranged at the top of a spinning chamber, an inlet for precipitating liquid leading into the chamber, an outlet for the precipitating liquid at the lower end of the chamber", a by-pass means located above the lower end of. the spinning chamber, whereby approximately 90% of the precipitating liquid may be deviated from said chamber, and meansfor returning said used precipitating liquid to a; storage tank the" entire system being closed so thatairisexcluded.

3. An apparatus as set forth in claim 2, the approximately 10% remainder'of th'e precipitating liquid being rich in ammonia from the euprammonium solution used, and means to recover said ammonia, the entire system except the portion of the apparatus handling the said 10% of the precipitating bath being closed so that air is excluded.

4,. An apparatus as set forth in claim 2, the approxmately 10% remainder of the precipitating liquid being rich in ammonia from the cuprammonium: solution used, and means to recover said ammonia, the entire system except the portion of the apparatus handling the said 10% of the precipitating bath being closed so that air is excluded.

AUGUST HAfiTMANN. WALTER HOFINGHOFF. 

